What does the cryptic crossword clue "Part of body overcome by chemical imbalance (4)" mean?

The definition is "Part of body". The wordplay uses a hidden word. Hidden in "part of body overcome by chemicaL IMBalance" The answer is LIMB.

Part of body overcome by chemical imbalance (4)

Guardian Cryptic #29094 | 24 Down | 2023-06-12 flower